Percentage of observations where the VFR minimums for ceiling and visibility are met: visibility of 5 mi or more and a ceiling of 3,000 ft or more. Only observations between sunrise and sunset are taken into account.
Marginal VFR conditions (%)
Month
Average
2024
2023
2022
2021
2020
January
73.9
80
61
68
77
68
February
76.0
71
79
69
73
81
March
75.7
61
69
72
86
73
April
76.0
78
68
66
92
May
81.1
83
86
84
84
June
81.1
63
77
86
91
July
85.3
75
91
80
79
August
90.4
81
88
91
96
September
86.5
72
88
90
88
October
88.9
84
84
94
93
November
85.1
91
85
80
89
December
83.7
82
79
85
77
Average
80.9
69.7
75.8
79.9
82.8
84.7
Marginal VFR conditions or better during daylight period
Percentage of observations where the MVFR minimums for ceiling and visibility are met: visibility of 3⅛ mi or more and a ceiling of 1,000 ft or more. Only observations between sunrise and sunset are taken into account.
Maximum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-2.9
-1
2
-2
-1
-1
February
-2.8
0
-2
-1
-1
-1
March
2.0
5
1
3
4
1
April
7.7
9
8
9
7
May
13.8
14
15
14
14
June
19.9
19
20
23
21
July
24.0
26
25
22
24
August
23.8
22
24
25
25
September
19.6
21
20
20
20
October
14.0
15
16
15
13
November
6.9
6
8
8
9
December
1.5
4
3
2
4
Average
9.7
1.0
11.2
11.9
11.5
11.2
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-9.8
-7
-5
-11
-5
-8
February
-10.9
-7
-11
-9
-8
-9
March
-5.3
-2
-4
-5
-5
-5
April
0.1
0
1
1
-1
May
4.5
4
5
4
6
June
11.2
11
12
13
13
July
16.0
18
16
14
16
August
15.9
15
17
17
16
September
11.5
13
11
13
11
October
6.6
8
8
7
6
November
0.1
-1
2
2
1
December
-5.4
-2
-2
-5
-2
Average
2.2
-6.7
4.0
4.0
4.0
3.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
48.3
40
47
59
47
56
February
35.3
39
35
44
35
29
March
29.3
31
30
32
25
33
April
22.1
10
32
32
10
May
17.4
19
14
16
19
June
14.9
19
19
11
8
July
11.0
16
11
19
13
August
11.9
27
15
5
7
September
14.5
22
16
18
10
October
14.4
26
5
6
10
November
28.6
30
27
33
14
December
36.8
37
43
35
46
Average
23.7
36.1
25.1
24.1
21.7
19.3
Precipitation during daylight period
Percentage of observations with observed rain, drizzle, snow or hail. Only observations between sunrise and sunset are taken into account.
Wind speed (knots)
Month
Average
2024
2023
2022
2021
2020
January
10.8
11
11
11
9
10
February
11.0
12
10
12
10
10
March
11.4
12
10
11
12
12
April
10.8
9
11
11
11
May
10.3
12
9
10
11
June
9.6
10
8
10
10
July
8.6
8
10
9
8
August
8.7
9
9
8
10
September
9.3
9
9
10
11
October
9.3
9
8
8
10
November
11.3
10
12
10
11
December
10.7
11
13
10
11
Average
10.2
11.6
9.8
10.0
9.8
10.4
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2024
2023
2022
2021
2020
January
288°
346°
271°
328°
308°
February
309°
315°
269°
286°
252°
March
218°
345°
246°
251°
330°
April
323°
349°
005°
328°
May
296°
286°
313°
263°
June
094°
186°
213°
190°
July
184°
223°
211°
185°
August
187°
190°
217°
242°
September
289°
274°
209°
217°
October
239°
210°
327°
224°
November
251°
263°
257°
234°
December
276°
025°
274°
231°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.